The present invention relates generally to tone data generating techniques, and more particularly to a method and device which are suitable for causing a general-purpose arithmetic processor, such as a CPU, to execute tone generating processing.
In many electronic musical instruments today, microprocessors are used to execute tone generating processing. In some cases, the microprocessors even execute processing to impart effects to tone data formed through the tone generating processing. It has long been a common practice, in the art, to implement such microprocessors by dedicated hardware (for example, tone generator LSI or DSP) having a circuit structure depending on a particular tone generating method employed (for example, waveform memory or FM synthesis method).
However, thanks to the recent improvement of CPU's computing capability, electronic musical instruments have appeared where the CPU loaded in a general-purpose computer or dedicated tone generating device is programmed to execute necessary tone generating processing. Here, such a tone generating device or method will be called a "software tone generator", while the traditional tone generating device or method will be called a "hardware tone generator".
In the software tone generator, the CPU must concurrently execute the tone generating processing and various other processing. Thus, in cases where a general-purpose computer is used to implement the software tone generator, it is desirable to carry out the tone generating processing on an operating system having a multitask function (e.g., Windows 95 (trademark) of Microsoft Corporation) in order to assure that the tone generating processing is executed without being influenced by the other processing.
But, in fact, operating systems having no multitask function (e.g., Windows 3.1 (trademark) of Microsoft Corporation) are widely used today, and there is a great need for the tone generating processing to be executed on such operating systems. With these operating systems, the execution of the tone generating processing tends to be often delayed by an influence of the other processing, which could result in a significant hindrance to the tone generation.